NA+-K+ AND HCO3- ATPASE ACTIVITY IN RETINA - DEPENDENCE ON CALCIUM AND SODIUM

  • 1 January 1977
    • journal article
    • research article
    • Vol. 16  (12) , 1151-1154
Abstract
With the use of homogenates of whole rate retina, the activities of Na+-K+- and .**GRAPHIC**. ATPases were measured in media containing different concentrations of Ca2+ and Na+. In comparison to the Na+-K+ ATPase activity observed in the presence of 2 mM Ca2+ and 130 mM Na+ the omission of Ca2+ from the medium led to a 16-fold increase in activity. The omission of Ca2+ and the reduction of the concentration of Na+ in the medium to 25 mM also resulted in an increase in activity of 9-fold. This study demonstrated, for the 1st time, the existence of a .**GRAPHIC**. stimulated ATPase activity in the retina. These results were discussed in relation to recent observations on the effects of Ca2+ and HCO3 free media on the electrical and metabolic activities of the rat retina.